Alkylation of phenols



March 13, 1951 w. N. AXE

ALKYLATION oF PHENoLs Filed Nov. 16, 1945 N. AXE

IN VEN TOR.

ATTORNEYS Patented Mar. 13, 1951 UNITED "-.fsTAiTEs PAT/ENT f oFF-ICE #12,544,818 "l'lY'IoN oil Y'linienoLs :William N.'ffAxei,l"Bartlesville, Okla., assignor to ,jzPhillipsf Petroleum Company; afcorporation of V'Delaware vAp;ilfcatioiiNivfmber 1e, "19451; seriarNofzsoz 13 claims. (0152604524) is the principal reaction. Preferably the catalyst consists of '70 to 90 per cent aqueous orthophosphoric acid saturated with boron nuoride.

The boron fluoride-ortho-phosphoric acid catalyst of this invention is prepared by adding gaseous boron nuorlde to the acid or more preferably to concentrated aqueous solutions thereof. The resulting reaction is exothermic, and the rate of BFg addition is usually controlled, together with external cooling of the addition product, to avoid temperatures much above about 200o F. which may prolong the preparation. Saturation of the acid and completion of the preparation is denoted by escaping BFs fumes.

The exact mechanism of the addition reaction and/or the formulas of the compounds formed in the preparation of the catalyst are not always known, but it is fairly Well established that two reactions occur. One is the formation of boron fluoride hydrate with any water present with the A ortho-phosphoric acid; the other is the formation of an addition compound of boron nuoride and ortho-phosphoric acid containing approximately equiinolecular proportions of each. For example, when using 85 per cent acid, the amount of boron iiuoride absorbed corresponds to formation of the Bilal-131304 addition compound plus sumcient boron liuoride to form a hydrate with l5 weight per cent of water present. At saturation under the above-mentioned conditions, this hydrate represents an II`1G:BF3 mol ratio of slightly over 1:1.

The ortho-phosphoric acid employed may be the concentrated acid ranging from the 85 per cent acid of commercial grade up to about 100 per cent l-I3P04. Or, aqueous solutions containing `as little as 70 per cent I-lcPOi may be employed.

For most applications, 35 per cent phosphoric acid of commerce is preferred.

In this connection, it has been denitely established that the hydrate is not the principal active ingredient of the catalyst, although it may promote and/or cooperate in the activity of the BF3H3PO4 complex in some obscure fashion.

Thus, boron fluoride hydrate to which phosphoric acid has been added (regardless of the proportions) is relatively inactive and does not exhibit the qualities of the catalyst prepared according to this invention. Similarly, when an active catalyst of my preferred composition loses appreciable quantities of boron fluoride durin use, it becomes less active.

The addition or" a slight excess of phosphoric acid to a normally active catalyst results in a condition approximating spent catalyst. On the other hand, addition of boron fluoride hydrate to an active catalyst does not materially impair its activity. From this evidence it may be deduced that decomposition of the phosphoric acid complex (BFS-531204) is the primary reaction controlling catalyst life, and this complex is therefore the essential ingredient of the cata-A lyst composition.

' As a consequence, my preferred catalysts do not reach maximum activity until the phosphoric acid solution is saturated with boron Iiuoride. Thus, it will :be apparent that from the standpoint oi both the catalyst cost and activity, it is `more efficient to employ concentrated acid solutions to decrease the quantity of the boron nuoride consumed y in hydrate formation. On the other hand, 95 to 10G per cent phosphoric acid is `relatively expensive and tends to solidify at moderately 10W temperatures so that 70 to 90 solved in the diluent phase.

However, after addition of boron fluoride, the iinished catalyst is a heavy liquid Which shows no tendency to solidify at temperatures as lowr as 40 F.

As the olefin I may employ aliphatic olens especially low-boiling oleiins having from 3 to 5 carbon atoms per molecule, namely, propylene, normal butylenes, isobutylene, and any of the amylenes. I may also employ cyclic olelins especially those having iive or six carbon atoms in the ring such as cyclopentene and cyclohexene and their alkyl derivatives.

The olefin may be pure or may be admixed with inert material, usually the normal parafns, in which case such inert material merely functions as a diluent in the reaction zone. Where the inert material is propane, it passes through the reaction zone and appears in the gases which are uncondensed in the overhead condenser and are vented from the condensate accumulator. In the case of normal butane, it may or may not be thus removed from the reaction zone depending on the temperature and pressure conditions prevailing therein. Presence of such inert material in the olefin stream is desirable in many respects. Thus, it enables avoidance of the trouble and expense of concentrating the oleiin to separate it from paraffin. Furthermore, it serves to reduce the local concentration of the olefin in the reaction zone. This latter eect is especially advantageous where the olen is introduced in gaseous form to the reaction zone.

I prefer to carry out the process of the present invention in the presence of a large volume of normal paraffin hydrocarbon as a diluent. This serves to cut down side reactions and to moderate the reaction with consequent reduction of losses and increased yield of the desired material. It also serves as a solvent for the olefin and as a suspension medium for the phenol. to keep the temperature rise from being excessive. In addition the diluent enables very simple temperature control by holding the reaction mixture at the boiling point of the diluent and condensing and returning the volatilized diluent to the reaction zone. It is seldom feasible to eifect such temperature control by volatilization of the olefin since ordinarily the process is carried out under such conditions that the olefin concentration is kept too low to permit this result.

I'he reaction may be carried out in any suitable Way. The phenol and the olefin may be fed to the reaction Zone separately or in admixture with one another. The phenol may be introduced in the liquid state where it is suiliciently low-melting, or especially where it is a solid at the reaction temperature it may be introduced as a dispersion in the diluent. Since the phenols have limited solubility in the normal paraiiins used as diluent, they may be dispersed as either solid or liquid in the diluent, it being ordinarily not feasible to use such proportions of the phenol and the diluent to cause all of the phenol to be dis- The olefin may be introduced over a long period of time in the case of a batch operation or continuously in a continuous-type operation.

Ordinarily the phenol is suspended in the diluent and the resulting suspension is commingled with' the liquid boron fluoride-phosphoric acid and with the olefin in the reaction zone. The mixture is agitated in order to keep the several phases in intimate contact with each per cent concentrations are often preferred. :Ii other for a period of time sufficiently extended to It also serves "ffinsure the completionof1-1thelfdesired reaction. 'fiiible-portion mayfcontaini the unreacted-'iiphenol 'fI-Theereaction-zone iseprovfided with anylsuitable ella'cidf product while thelalkali-insoluble Yfraction --'-coolingfmeanssuch as-'tloe usual vcooling jacket 1 maytcomprise'any of-fthe -poly-alkylphenolssuch :,and/orcooling ooilsfbut more preferably a reflux -`\as' the dialkylatedephenols,thatmaylbeformed -v condenser arrangement asdescribed above. ggf-in small quantities.

lIt is'-preferred that the concentration of vfree The-'unusual effectiveness cfa-the present cata- -f'orunreactedolefin inthereaction zone be kept lyst may be dueto further complex compound Lat a Sliitabli7 10W; leVel'in orderto prevent Side "formationbetween-thecatalystcompositionand '--reactionsiv especially polymerization. For' eXam- #the-'phenolicintermediate. fThus-, on contacting -ple,1theolenconcentration in the reaction Zone ioilthe'catalyst-#with phenol in the-presencef-of a "may/bekent: belOW Weightperf-cent. In aY condiluent--ntheabsence of-o1en, a pronounced-abu--tinuous operation. thismay be accomplished by --isorption of heat is observedas the phenol and y-usingfan-externalfeedffmole'ratio of from 2l to 6 -fcatalystphases combine. The-nature'of this re- -moles of the nhenoiper 'mole of the olen." Befact-ion is-onknown'but it is apparent that the `Y-cause of theeonsumption of olen inthereaction lealkylation 4act-uallyoccurs` in the Anon-hydrocar- `zone the-mole ratio ofphenolto'olen therein i'bonphase. lmay-loe as high as vSL00 to v`1 or even hgherp In a In a'-fgeneral"embodimentef of this' invention `v'batch operation the desiredlow concentration of *'--Wherein a batch/procedure is employed`r theseolefin isreadily obtained'byv initially introducing `-1ectedphenol is suspended in'A from about-'200 to the entire amount of thephenOl into the reaction ":'1000 f ce. of`Y inert diluent such Aas npentaneeper zone and adding .theifoleuigradually over a pro- Lmole ofthe phenol.' iCatalyst prepared fas-i delOnged period of time, say one to three hours. An scribed above is added in amountequivalent to .'artiiicially high ratio of phenol to'olen may be labout 10 tof-100A cc. per mole uof the'phenol 'maintained in the reaction zone in`any suitable Lchargedeand thel mixture is thoroughly agitated Way; .for eXeinlOle byieeyeling reaction mixture lvvhile charging either gaseous or'liquidolefin at from a point at which olen is substantially con- Such irate als topmvid-e moderate boiling of the sumed to a point adjacent the point'of inlet 0f diluent. "Areflux condenser is provided to confresh olefin;inside'oroutsideof the reactorf. Such `dense the' diluent-'and return'it to thereaotion an ertifieiallyhigll ratio may also be obtained by 'zonev Ordinarilyno other Ameans of temperature Vlfl'jecting the olen inl'smell StlemS at ci multi- 30"control isrequired. "Uponaddition' of 'an-equi pliety- 0f peints nlOneTV the le'aCtOl ZOne. These ""molecular amountiof oleiin, the reaction is eXpedientS may be einDlOyed in addition t0 mainj stopped and water is Aadded to decompose and retenanceof'theexternal mole feed ratio in excess -move thel catalyst, The di1uent is then removed of one, sav at from 2te 1 to 6 te 1 as described -by-distinationfandsthe crude phenolic product is ribOVeipur'ied'by distillation and/or recrystallization. The proportions/of reactants,catalyst and dilu- In many instances a preliminary treatment with entemblOyeCl may be VIied'OVei Wide limits Withl0 per vcent caustic-solution may be employed to out departing from the spirit'of the invention. segregate alkali-soluble and alkali-insoluble prod- Ordinarily; I lprefer to useirom"200 to' 1000 cc. of ucts Y All monoalkyl-substtution products of pnethe normal `C4 t0 C8 paraffin'dluent bei' H101@ 01101; cresols, xylenolsyetc; 'are soluble in A'alkali (gram moleenlei" Weight)l Ofthe- DhenOl and t0 `While phenol ethersand `certain polyalkylated use the Catalyst in ammini?banging YflOIIlv l0 t0 Y-Yproducts such'asftrietert-butylphenols"are insolu- 100 cc. per'mole of the phenol. The total amount l b1e of olen introduced to the reaction 'zone isf often While batch-reactions are oftenmost consnbstentelly equimoleeulal te'tlle DbeIlOl but it 45uvenient for thealkylation*oftphenolic materials, may be considerablylesswthan the eqnimoleeulal -continuouslprocessesare alsovr contemplated. amount. .-In a4 continuousoperation itmay run *Phenolic intermediatesA suitable foruse in the as loW-aslO percent oftheamount equimolecular represent process include*rnonohydric phenols such t0 the phenol Ina batch Operation as described 5(5"as'ph'enol and its alkyl'derivatives such as cresols, ,inA the examples it isl convenient tov use between ""xylenolsr; etc'; as -w'ellas dihydricphenols such as about .90and aboutlooper cent of the stoichioecatechol, hydroquinone andresorcino1- Aside metric amount ofl olen. y Use of a molarden- "from'allayl derivatives itis preferredto use vunciency of-olefin relative to phenol is `often desirasubstituted phenols.

ble, as explained above althoughwhen such a de- .55 "The diluents of'thisinvention are'selected parciency iseemployed .the unreacted phenolmust aflinic hydrocarbonspreferablynormal'Crto Ca be separated `from the. reaction eiiiuent to effect paraffns such as n-butane, n-pe'ntane, n-heXane purification ofv the product 'alkylated phenol. or'fractions of natural'gasoline free of alkylata- `lecovery and Yrecycle of the unreactedphenol *ble isop-arainns, Where a normally gaseous dilurnay impose an objectionable loaden therecovery oentsuoh'as normalbutane is used the'pressure i land `ieeyele Ysystenfrfwhere. the famount of .-unre- "must be maintained .s'umciently high to hold it -acted'phenol is excessive but ordinarily .this is not in liquid phase.Y lNormal pentane is preferred bea serious "objection-:to the use of adeciency of cause its boilingpoint gives a suitably lowireacolen. tion temperature at atmospheric pressure.

v'ihefreaetionmixture iswithdrawn Afromfthe 65 Conditions'of temperature and pressure may reaction Zone and is treated in any suitable-way vary within considerable-.limits depending on the to recover the alkylatedephenol product and the system under consideration. It is preferred to diiuent and. unreacted phenol. VCatalyst is re- .adjust the pressure in such aiway that the boil- .moved either bylsettlingor byhcaustic and/or ingpoint of the normalparaflin hydrocarbon Waterwashing or .by a combination ofthese prodiluent is:V Within the preferred operating temcedures after` .Which .thenormal .paraln hydro- .-perature range; allowing the diluent to boil and oarbondiluent is `removed .by fractional distilla- .condensing and returning the volatilized diluent tion. If desiredtheresiduemay be treated'with isa. most. effective and .convenient method .of .causticsolution.,toseparate it intoalkali-soluble holding the desired temperature.at aconstant and alkali-insoluble fractions. The alkali-.solulevel. Ordinarily `temperaturesLof trom" 50 'F'.

to about 150 F. are adequate with temperatures of about 85-120 F. being preferred. Pressures may vary from atmospheric to about 200 pounds per square inch gage or higher. In batch reactions low superatmospheric pressures are preierred. In continuous reactions, liquid phase contacting is preferred between the olefin and phenol; in such type of operation the pressure must, of course, be sufficiently great to hold the olen in liquid phase. In batch reactions gaseous olen may be added to the reaction zone.

ln the drawing, a phenol from tank I, olen from tank 2 and diluent from tank 3 are fed into reactor 4 by the lines shown. The olefin fed in gaseous form via line 5 or in liquid phase via line 6 may be admixed with the suspension of phenol and diluent flowing in line l or may be separately introduced to reactor Il via line 8 entering the reactor at a single point or at a multiplicity of points as shown. Reactor 4 is supplied with catalyst from tank 9 via line I0. Reactor Il is provided with stirring means for attaining intimate admixture oi phases. The vapors leaving the top of reactor li may be condensed and returned in the manner indicated, any uneondensed gases such as traces of BFs being vented as shown. The reaction mixture is passed to a catalyst removal unit II. The resulting mixture which contains the alkylphenols and any unreacted phenol is passed to fractionation system I2 where the diluent is recovered for recycle via line I3, The mixture of phenols may then be passed via line I4 to purication unit I5 wherein the product alkylated phenol is recov- Y ered. Means (not shown) for recovering and recycling the unreacted phenol may be provided.

Example 1 Three moles of phenol and 750 cc. of n-pentane were charged to a Z-liter glass reactor equipped with a motor-driven stirrer. To the agitated suspensionof phenol and pentane there was added cc. of catalyst comprising syrupy phosphoric acid saturated with boron fluoride. A drop in temperature of 12 F. was observed at this point due to solution or reaction between the phenol and the boron fluoride-phosphoric acid complex. The introduction of gaseous isobutylene into the reaction mixture resulted in an evolution of heat, raising the temperature to the boiling point of the pentane diluent. The alkylation reaction was discontinued after the addition of 2.7 moles of isobutylene and the pentane solution was washed with caustic solution followed by water. Upon removal of the pentane diluent by distillation, a low-melting solid was obtained which was recrystallized from n-pentane at the temperature of an ice-salt bath. The melting point of the crystalline product was ST5-98.5 C. (unconl. This product is completely soluble in aqueous alkali and its melting point corresponds to that of p-tert-butylphenol. The yield of pure recrystallized product amounted to 80 per cent of theory based on isobutylene charged.

Example 2 One mole of catechol and 1000 cc. of n-pentane were charged to the reactor of Example 1. With enicient stirring, 100 cc. of catalyst consisting of 85 per cent phosphoric acid saturated with boron lil diluent serves only as a solvent for the isobutylene and a means of maintaining the temperature of reaction below 97 F. After the addition ofthe isobutylene, the pentane was mechanically separated from the reaction phase. The catalyst was removed from the heavy oil by water extraction, after which the oil was dissolved in 10 per cent sodium hydroxide solution, No alkali insoluble material was obtained; hence, the product was recovered by neutralization. The recovered oil was distilled at 3 mm. pressure, the entire product distilling between MiO-160 C. The distillate crystallized at room temperature and nal purication was eiected by recrystallization from isooctane. The purified material melted at 54-55" C. (uncor.) and was found by conventional tests to be identical with an authentic sample of 1,2dihydroxy-S-tert-butylbenzene. The yield of tert-butyl catechol was about per cent of the theory based on catechol charged.

Example 3 Three moles of phenol and 700 cc. of n-pentanc were charged to the Z-liter reactor of Example 1. On addition of 50 cc. (92 g.) of catalyst, prepared by saturating per cent phosphoric acid with boron fluoride, a pronounced absorption of heat occurred as the phenol and catalyst phases united to form a single phase mechanically separable from the pentane diluent. Three moles of gaseous propylene was added to the reaction mixture over a period of 1.5 hours at a reaction temperature range of S35-96 F. The resulting hydrocarbon solution of alkylated phenol was Washed with water prior to removal of the pentane by distillation. The depentanized product was then treated with 10 per cent sodium hydroxide solution to separate the alkylate into alkali-soluble and alkali-insoluble fractions. The alkali-soluble material was fractionally distilled at atmospheric pressure to give an overhead product of orthoand para-isopropylphenol boiling at 19g-230 C. (uncor.). The yield of isopropylphenol amounted to 74 per cent of the theory based on phenol.

Emample 4 Three moles of rn-cresol (325 g.) and 750 cc. of n-pentane were charged to the 2-liter glass reactor. Catalyst (50 cc.) consisting of 85 per cent phosphoric acid saturated with boron uoride was added to the cresol solution and mechanical agitation was employed to mix the two phases during the addition of 3 moles of gaseous isobutylene. The reaction mixture was Washed with water to remove the catalyst after which pentane and m-cresol were recovered by distillation at atmospheric pressure. was separated from higher alkylation products by treatment of the total product with l0 per cent sodium hydroxide. The yield of tertiarybutylcresol was found to be 62 per cent of the theory based on cresol consumed. Material balance values indicated that the alkali insoluble material contained 2 butyl groups per mol of cresol.

Example 5 The procedure of Example 4 was employed to alkylate p-cresol with isobutylene. In this instance 133 g. of cresol was recovered unreacted indicating the reaction of 2 moles of isobutylene per mole of p-cresol. The reaction product was substantially insoluble in 10 per cent sodium hydroxide which is characteristic of the di-tertbutylcresols.

Mono tert loutylcresol` Three moles Jof phenol (284- g`.)` were 'suvspendedf in "100 cc; of n-pentaneand charged tothe '2L-liter glass reactor:- While mechanically' agit'ating the phenol-pentan'e mixture; A'50' cc. ofr boron fluoride#A phosphoric 'acid' catalyst was added and-heatab= sorption was noted. Three molesof cyclohex'ene overa periodof 4' hours-while maintaining the temperaturei below abouti 97 i The', pentane` solution of product was'washe'd with water .to dei' stroy the catalyst andthe pentane was recovered by'distillation." A separationof orude product' into alkali'lsoluble and' alkalieinsolublematerial was eiected withlO per 'cent'sodium hydroxide."

The Aalkali-soluble"`material was 'separatedf into ortho-"and paralcycloh'exylphenol 'by "virtue of the relative'insolubi1ity"'of"the para isomer in cold n-pentane. Both of4 the isomers'were recrystallized from'isooctane and were' identiiie'd` 1. The process-of introducing a single alkyl.

group into a phenol which comprises'contacting" y a phenol andzanrfolenninithepresen'ceof normal pentane as a diluent and in the presence of a catalyst consisting of the productsresultingtrom the'saturation of concentrated. aqueous-orthophosphoric acid containingvfrom 70 to 90% HaPGlr with bor-on iluoride, maintaining the :result-V ingmixturecat a temperature-ot from 85=to 120 E. at 1a pressure allowing boilingof the reaction' mixture', while maintainingthevolein concentration below 5 Weight per cent in the reaction mixture and thereby eiectin'gi'ntroduction of a singlecalkyl group corresponding to said olefin into-lthe benzene nucleussof said vphenoli'afsithe principal reaction, ands-recovering 'the resulting product containing one introduced alkyl group in an amount in excess of per cent of the theoretical yield.

2. The continuous process of introducing a single alkyl group into a phenol which comprises continuously introducing to a reaction Zone a phenol, an olen and a normal parailin hydrocarbon diluent having from four to eight carbon atoms per molecule, the molecular proportions of said phenol and said olen introduced to said zone being such as to give an external mole ratio of from 2 to 6 moles of phenol per mole of oleiin, continuously maintaining in said zone a catalyst consisting of the product resulting from the saturation of concentrated aqueous orthophosphoric acid containing from 70 to 90% H3PO4 with boron fluoride, maintaining said reaction zone at a temperature of from 85 to 120 F. by boiling the same and thereby volatilizing said diluent, condensing the volatilized diluent and returning the liquid condensate to the reaction zone, thereby effecting introduction of a single alkyl group corresponding to said olen into the benzene nucleus of said phenol as the principal reaction, continuously withdrawing the reaction mixture from the reaction zone and recovering therefrom -the Ialkylate'dwphenok coni-raining one introducedalkyl group so'producedin an amount `in .excess of 50 per cent ofthe theoretical yield.

3. The processiof making para-tertiary butyll phenolwhich comprisescontacting phenol and isobutylene at a'reaction temperature offrom'85 to 120 F. in the presence of a catalyst consisting of'the product prepared'by saturating concentrated aqueous orthophosphoric acid vcontaining from 70 to 90%' l-IaPOr with'boron uoride, and in thepresen'ceof boiling normalpentane diluent,` while `maintaining the isobutylene concentration c below=5 weight per-cent vin thel reaction mixture andY thereby eiecting' alkylation of the phenolVH with the isobutyleneto'form para-tertiary butylphenolas the" principal'reac'tion product, and recovering' the'said para-tertiary butylphenol -in an amount'in excess of `50 per cent of the theo-`V retical yield:

4. The process of making isopropylphenolv` f which comprises contacting phenolv andI propylene at a reaction temperature rof from to'120-F.^

in theA presence' ofa catalyst-consisting of the product' prepared by saturating concentrated aqueous vorthophospho'ric acid containing from 70 to 90% `I-I1sPO4-wl'th boron luorida'and in the) presence of boiling normalfpentane diluent,whilev maintaining the propyleneconcentration below; 5 weight percent in the reaction mixture and thereby `effecting alkylation Iof the phenol with' the propylenef to form risopro'pylphenol as the principal freactionfproduct, andV recovering 'said isopropylphenol 'man-'amount' in excess iof' '50 per cent of the theoretical'yield.

5. The processofmakingY tertiary'butylcresol which comprises contacting m-cresol and isobu.- tylene at a reaction"teniper`atureoi frorrr'a'to 120 F. in thev presence of a catalyst consisting of theproduct prepared` by saturating concentrated aqueousV orthophosphoricacid containing: from '70 to H3PO4 with boron fluoride, and in the! presence of'boilingfnormal pentanediluent, while isobutylene to'rform 'tertiary butyl cresol asthe principal. reactioneproduct; land recovering? said' tertiary butyl cresol vin van amount in excess-'of l' 50 per'centof the theoretical yield;

phenol which comprises admixing with a suspension of phenol in'normal pentane as a diluent a catalyst prepared by saturating 85 per cent orthophosphoric acid with boron iiuoride and adding isobutylene to the resulting mixture over a prolonged period of time so as to maintain the isobutylene concentration below 5 weight per cent in the reaction mixture, holding the resulting mixture at the boiling point and at substantially atmospheric pressure and condensing and returning the volatilized normal pentane to the reaction mixture during said addition of isobutylene and therebymaintaining the reaction temperature substantially at the boiling point of normal pentane, the proportions of said materials being such that there is present between 200 and 1000 cc. of normal pentane and between 10 and cc. of said catalyst per mole of phenol and that the total amount of said isobutylene is between about 90 and about 100 per cent of that equimolecular to said phenol, and recovering para-tertiary butylphenol in an amount in excess of 50 per cent of the theoretical yield.

'7. The process of introducing a single alkyl group into a phenol which comprises contacting a phenol and an olefin with a catalyst the essential catalytic ingredient of which is the addition compound of BFS and H3PO4 in approximately equimolecular proportions in the presence of a normal paran-ln hydrocarbon diluent having from four to eight carbon atoms per molecule, maintaining the reaction mixture at a temperature of from 85 to 120 F. by boiling the same and thereby volatilizing said hydrocarbon diluent, condensing the volatilized hydrocarbon diluent and returning the resulting liquid condensate to the reaction zone, while maintaining the oleiin concentration below weight per cent in the reaction mixture and thereby effecting introduction of a single alkyl group corresponding to said olen into the benzene nucleus of said phenol as the principal reaction, and recovering the resulting product containing one introduced alkyl group in an amount in excess of 50 per cent of the theoretical yield.

8. The process of introducing a. single alkyl group into a phenol which comprises contacting a phenol and an olefin with a catalyst the essential catalytic ingredient of which is the addition compound of BFa and HaPO4 in approximately equimolecular proportions in the presence of normal pentane as a diluent, maintaining the reaction mixture at a temperature lying within the range of from 85 to 120 F. by boiling the same and thereby volatilizing said normal pentane, condensing the volatilized normal pentane and returning the resulting liquid condensate to the reaction zone, while maintaining the oleiin concentration below 5 weight per cent in the reaction zone and thereby effecting introduction of a single alkyl group corresponding to said olen into the benzene nucleus of said phenol as the principal reaction, and recovering the resulting product containing one introduced alkyl group in an amount in excess of 50 per cent of the theoretical yield.

9. The process of introducing a single alkyl group into a. phenol which comprises contacting a phenol and an olen with a catalyst consisting of the product resulting from the saturation of orthophosphoric acid of atleast 70 per cent concentration with boron uoride, said catalyst being employed in an amount ranging from to 100 cc. per gram molecular weight of said phenol, in the presence of normal pentane as a diluent,

said normal pentane being employed in an amount ranging from 200 to 1000 cc. per gram molecular weight of said phenol, maintaining the reaction mixture at a temperature within the range of from to 120 F. by boiling the same and thereby Volatilizing said normal pentane, condensing the volatilized normal pentane and returning the resulting liquid condensate to the reaction zone, while maintaining the oleiin concentration below 5 weight per cent in the reaction zone and thereby eiecting introduction of a single alkyl group corresponding to said olen into the benzene nucleus of said phenol as the principal reaction, and recovering the resulting product containing one introduced alkyl group in an amount in excess of 50 per cent of the theoretical yield.

l0. The process of claim 7 wherein tertiary butylcatechol is made by alkylating catechol with isobutylene. v

11. The process of claim 7 wherein cyclohexylphenol is made by alkylating phenol with cyclohexene.

12. The process of claim 7 wherein said olen is selected from the group consisting of propylene, the butylenes, the amylenes, cyclopentene, cyclohexene, and the alkyl derivatives of cyclopentene and cyclohexene.

13. The process of claim 12 wherein phenol is alkylated.

WILLIAM N. AXE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,008,032 Niederl July 16, 1935 2,146,667 Atwell Feb. 7, 1939 2,192,015 Nieuwland Feb. 27, 1940 2,240,583 Sparks et al May 6, 1941 2,283,465 Schaad May 19, 1942 2,351,347 Luten June 13, 1944 2,370,810 Morrell et al. Mar. 6, 1945 IEOREIGN PATENTS Number Country Date 451,359 Great Britain Aug. 4, 1936 453,422 Great Britain Sept. 4, 1936 

1. THE PROCESS OF INTRODUCING A SINGLE ALKYL GROUP INTO A PHENOL WHICH COMPRISES CONTACTING A PHENOL AND AN OLEFIN IN THE PRESENCE OF NORMAL PENTANE AS A DILUENT AND IN THE PRESENCE OF A CATALYST CONSISTING OF THE PRODUCT RESULTING FROM THE SATURATION OF CONCENTRATED AQUEOUS ORTHOPHOSPHORIC ACID CONTAINING FROM 70 TO 90% H3PO4 WITH BORON FLUORIDE, MAINTAINING THE RESULTING MIXTURE AT A TEMPERATURE OF FROM 85 TO 120* F. AT A PRESSURE ALLOWING BOILING OF THE REACTION MIXTURE, WHILE MAINTAINING THE OLEFIN CONCENTRATION BELOW 5 WEIGHT PER CENT IN THE REACTION MIXTURE AND THEREBY EFFECTING INTRODUCTION OF A SINGLE ALKYL GROUP CORRESPONDING TO SAID OLEFIN INTO THE BENZENE NUCLEUS OF SAID PHENOL AS THE PRINCIPAL REACTION, AND RECOVERING THE RESULTING PRODUCT CONTAINING ONE INTRODUCED ALKYL GROUP IN AN AMOUNT IN EXCESS OF 50 PER CENT OF THE THEORETICAL YIELD. 